1. Technical Field
The present disclosure relates to a wiring board and an electronic component device having the wiring board.
2. Description of the Related Art
in the related arts, there are wiring boards for mounting electronic components such as semiconductor chips. In such a wiring board, terminals of a semiconductor chip are flip-chip connected to pads exposed from an insulating layer (see e.g., JP-A-2005-101137).
As will be described in an undermentioned preliminary matter, a coreless type wiring board is manufactured based on the following manner. That is, a wiring layer is formed on a temporary substrate through a copper foil, and the copper foil is wet-etched after the temporary substrate is removed. When the copper foil is wet-etched, a recess portion is formed in each outer edge portion of the wiring layer.
A sulfuric acid component of an etchant is apt to stay behind in the recess portion in the outer edge portion of the wiring layer. Accordingly, there is a problem that the sulfuric acid component may react with an atmospheric moisture content to turn into sulfate ions to thereby corrode the wiring layer or cause ionic migration.